Fucus vesiculosus L.

Last updated: 15 Apr 2016

Scientific Name

Fucus vesiculosus L.


Halidrys vesiculosus (Linnaeus) Stackhouse, Virsodes vesiculosum (Linnaeus) Kuntze, Fucus inflatus Linnaeus, Fucus divaricatus Linnaeus, Fucus excisus Forsskål, Fucus vesiculosus var. divaricatus (Linnaeus) Goodenough & Woodward, Fucus vesiculosus var. rigidus Wahlenberg, Fucus balticus C.Agardh, Fucus vesiculosus var. angustifolius C.Agardh, Fucus vesiculosus var. nanus C.Agardh, Fucus vesiculosus var. subecostatus C.Agardh, Fucus vesiculosus f. acutus Lyngbye, Fucus vesiculosus var. filiformis C.Agardh, Fucus vesiculosus var. alternans C.Agardh, Fucus vesiculosus var. grandifrons C.Agardh, Fucus vesiculosus var. ceratiformis Wahlenberg, Fucus vesiculosus var. chondriformis J.Agardh, Fucus vesiculosus var. balticus (C.Agardh) Areschoug, Fucus vesiculosus f. vadorum Areschoug, Fucus vesiculosus subsp. pseudoceranoides Areschoug, Fucus vesiculosus f. pseudoceranoides (Areschoug) Kleen, Fucus vesiculosus f. angustifrons Gobi, Fucus vesiculosus var. spiralis Farlow, Fucus vesiculosus f. racemosus Kjellman, Fucus vesiculosus f. subecostatus (C.Agardh) Kjellman, Fucus vesiculosus f. angustifrons Gobi, Fucus vesiculosus f. sphaerocarpus (J.Agardh) Kleen, Fucus vesiculosus var. sphaerocarpus J.Agardh, Fucus axillaris var. subecostatus J.Agardh, Fucus vesiculosus var. laterifructus Greville, Fucus vesiculosus f. angustifolius (C.Agardh) Kjellman, Fucus vesiculosus f. nanus (C.Agardh) Kjellman, Fucus vesiculosus f. filiformis (C.Agardh) Kjellman, Fucus vesiculosus f. plicatus Kjellman, Fucus vesiculosus f. subecostatus (C.Agardh) Kjellman, Fucus vesiculosus var. aestuarii Lami, Fucus vesiculosus f. balticus Levring, Fucus mytili Nienburg, Fucus vesiculosus f. balticus (C.Agardh) Dannenberg, Fucus vesiculosus f. limicola Collins, Fucus vesiculosus f. typicus Kjellman, Fucus vesiculosus f. elongatus Kjellman, Fucus vesiculosus f. subfusiformis Kjellman, Fucus vesiculosus f. latus Kjellman, Fucus vesiculosus f. abbreviatus Kjellman, Fucus vesiculosus f. fluviatilis Kjellman, Fucus vesiculosus f. lanceolatus Kjellman, Fucus vesiculosus f. turgidus Kjellman, Fucus vesiculosus f. terminalis Kjellman, Fucus vesiculosus f. subglobosus Kjellman, Fucus vesiculosus f. robustus Kjellman, Fucus vesiculosus f. flabellatus Kjellman, Fucus vesiculosus f. crispus Kjellman, Fucus vesiculosus var. rotundatus Kjellman, Fucus vesiculosus f. tenuis Kjellman, Fucus vesiculosus f. racemosus Kjellman [1]

Vernacular Name

Malaysia Bladderwrack, black tang, kelp, kelpware, rockweed, seawrack [2], paddy tang, paddy-tang, red focus, dyers focus, swine tang, sea ware, bladder, popping wrack, wrack, bladder wrack, bladder-wrack [1]
Sweden Blåstång [1]
France Fucus vésiculeux [1]
Germany Blasentang [1]
Portugal Trambolho, estalos, esgalhota, bagão, limbo-bexiga, bodelha [1].

Geographical Distributions

Fucus vesiculosus is commonly found in the southern Baltic Sea as roughly 90% of the total biomass. This species act as key species and nursery for fish juveniles, gives shelter and offers a foraging place for many other organisms [3]. The survival of bladderwrack is affected by several factors, such as wave exposure and regional differences. The high wave exposure resulting in thinner populations. The life spans of this species at North Sea coast is average three years while at the sheltered areas gave maximum life spans of 4-5 years. In addition, a single frond at Baltic Sea may survive up to 20 years in sheltered areas [4].

Botanical Description

F. vesiculosus consists of the entire thallus of the marine plant. [3]


No documentation.

Chemical Constituent

F. vesiculosus has been reported to contain polyphenols (e.g. phloroglucinol), mucopolysaccharides (e.g. algin, fucoidan) [5][6],  sulfuryl-, sulfonyl- and phosphonyl-glycosyl ester diglycerides, sterols (e.g. fucosterol), polar lipids, trace metals, particularly iodine (usually 0.03-1% by weight) [7], vitamins (mainly vitamin C) [8], potassium, magnesium, calcium, iron, zinc, and other minerals [9].

Plant Part Used

Thallus [2]

Traditional Use

Historically, F. vesiculosus or bladderwrack has been used in the dairy and baking industries, due to the gelling properties of the constituent algin. [9]

Another traditional use of bladderwrack is as a laxative. The alginic acid is a hydrophilic colloidal substance that swells to approximately 25-35 times its original bulk in an alkaline environment, and as a result, exerts a bulk laxative action. [2]

The F. vesiculosus fronds are dried as soon as possible after collection in preparation for use as dietary supplements. Marine algae have enjoyed a long usage in the materia medica of Europe and Asia (the Chinese have used bladderwrack for at least 4,000 years). F. vesiculosus is a rich source of iodine, and is traditionally used in weight loss and hypothyroidism [2][10][11]. The low incidence of goiter in maritime people has been attributed to the iodine content in bladderwrack [12]

Preclinical Data


Thyroid stimulating activity

F. vesiculosus is thought to stimulate the thyroid gland, thus increasing basal metabolism. Bladderwrack may also lower cholesterol levels as reported with in vitro and laboratory animal studies. [13][14]


Anti-HIV active polysaccharides and polyphenols have been isolated from F. vesiculosus. The constituents were reported to inhibit both HIV-induced syncytium formation and HIV reverse transcriptase enzyme activity in vitro. [15]

Hypoglycemic activity

A study has been reported that F. vesiculosus lowered blood sugar levels in laboratory animals. [16]

Bioadhesive effects

Polysaccharides from the aqueous extract of F. vesiculosus was reported useful in therapy for irritated mucus membranes in the pharynx region.  Results showed the absorption effects of these polysaccharides on mucus membranes, suggesting that this may account, at least in part, for the therapeutic effects of mucilage-containing plants in the treatment of irritated buccal membranes. [17]

Wound healing activity

In an in vitro model, a proprietary extract of F. vesiculosus has been reported useful in wound contraction and granulation. The extract promoted gel contraction by increasing the expression of integrin molecules on the fibroblasts surface and increased the relaxation time of the gels. [18]

Anticoagulant activity

Fucoidan is a constituent that has been identified in F. vesiculosus. The structure of this fucoidan has been noted to be identical to that isolated from another algae species, Ascophyllum nodosum. The latter has been noted to have in vitro anticoagulant activity [19], which may also be represented in bladderwrack. The anticoagulant activity is apparently dependent on the degree of sulfation of the molecule [20]. On a similar note, fucoidan has also significantly increased postischemic renal blood flow in a small rat study, demonstrating potential renoprotective activity [21].


No documentation.

Clinical Data

Clinical findings

There is limited clinical information on the use of F. vesiculosus in human subjects. A 60-day trial of obese subjects taking bladderwrack reported a significantly greater weight loss than those taking placebo. [10]


F. vesiculosus is safe in recommended dosages. However, it has been reported that marine based plants can contain various levels of iodine as well as traces of heavy metals such as arsenic.  It is important that the levels of iodine are listed on the product label to ensure safety. [22]

The ability of marine plants to accumulate heavy metals and other toxic elements is recognized. Manufacturing should include testing for these and other contaminants and use with caution when recommending bladderwrack or other seaweed products that may contain contaminants. Levels of iodine should also be listed on the product label to ensure safety. [23]

Side effects

There have been reports of seaweed causing contact dermatitis. [24][25]

F. vesiculosus overdoses may lead to hyperthyroidism, tremor, increased pulse rate, and hypertension. These effects are likely the result of an iodine overdose. The adult RDA for iodine 150mcg per day with an upper limit for iodine not to exceed 1,100mcg daily. [26]

Pregnancy/Breast Feeding

Do not use fucus in pregnancy and lactation due to the potential for marine plants to contain heavy metals, such as arsenic. [22]

Age limitation

Due to the potential for marine plants to contain heavy metals, such as arsenic,  concern is warranted when using F. vesiculosus in young children. [22]

Adverse reaction

No documentation.

Interaction & Depletion

No documentation.

Interaction with drug

No documentation.

Interaction with other Herbs

No documentation.


No documentation.

Case Report

Overdoses of iodine may lead to symptoms of hyperthyroidism, including weight loss, fatigue and frequent soft stools. These symptoms were reported in a 72 year old female following six months of ingesting a commercial kelp product [27]. Another report describes a 24 year old woman developing thyroid goiter after taking a proprietary product, which included 0.4-0.5 mg/day of iodine for three months [28]. Products where the iodine content is assayed should be used to avoid potential iodine toxicity problems.

F. vesiculosus may have effects on estrogen in humans. A case report in 3 women with abnormal menstrual cycles found that consumption of bladderwrack leads to changes in the regulation of the menstrual cycle by lowering the estrogen/progesterone ratio, increasing the length of the cycle and stimulating ovulation in pre-menopausal women. [29]


No documentation.

Poisonous Management

No documentation.

Line drawing

No documentation.


  1. Guiry MD. Fucus vesiculosus Linnaeus. In: Guiry MD, Guiry GM. AlgaeBase. [homepage on the Internet]. Galway: National University of Ireland; c1996-2016 [updated 2015 Dec 26; cited 2016 Apr 15]. Available from: http://www.algaebase.org/search/species/detail/?species_id=Tdaf6cbe1223d60de&sk=0&from=results
  2. Newall CA, Anderson LA, Philipson D. Herbal medicines: A guide for health care professionals. London: The Pharmaceutical Press, 1996; p. 124-126.
  3. Karlsson J, Eklund B. New biocide-free anti-fouling paints are toxic. Mar Pollut Bull. 2004;49(5-6):456–464.
  4. Torleif M, Lena K. Are Bladderwrack (Fucus vesiculosus L.) holdfasts that support several fronds composed of one or several genetic individuals?. Aquat Bot. 2004;3(80): 221-226.
  5. Nishino T, Nishioka C, Ura H, et al. Isolation and partial characterization of a novel amino sugar-containing fucan sulfate from commercial Fucus vesiculosus Fucoidan. Carbohydr Res. 1994;255:213-24.
  6. Anthony CD. The internal and external use of medicinal plants. Clinics in Dermatology. 2009;2(27):148-158.
  7. Thring TSA, Hili P, Naughton DP. Anti-collagenase, anti-elastase and anti-oxidant activities of extracts from 21 plants. BioMed Central. 2009;9:27.
  8. Bradley PR, ed. British herbal compendium: A handbook of scientific information on widely used plant. Dorset, England: Bournemouth, 1992; p. 37-39.
  9. Duke JA. Handbook of phytochemical constituents of GRAS herbs and other economic plants. Boca Raton, Florida: CRC Press;1992.
  10. Curro F, Amadeo A. Fucus vesiculosis L. nel Trattamento Medico Dell’Obesita e delle Alterazioni Metaboliche Connesse. Arch Med Interna. 1976;28:19-32.
  11. Moro CO, Basile G. Obesity and medicinal plants. Fitoterapia. 2000;71(Suppl 1):S73-S82.
  12. Burkholder PR. Drugs from the sea. Armed Forces Chem J. 1963;17(6):12-16.
  13. Tang ZL, Shen SF. A study of Laminaria digitata powder on experimental hyperlipoproteinemia and its hemorrheology. [Article in Chinese]. Zhong Xi Yi Jie He Za Zhi. 1989;9(4):223-5,198.
  14. Wang C, Yang G. Comparison of effects of two kinds of soluble algae polysaccharide on blood lipid, liver lipid, platelet aggregation and growth in rats. Zhonghua Yu Fang Yi Xue Za Zhi. 1997;31(6):342-345.
  15. Beress A, Wassermann O, Tahhan S, et al. A new procedure for the isolation of anti-HIV compounds (polysaccharides and polyphenols) from the marine alga Fucus vesiculosus. J Nat Prod. 1993;56(4):478-488.
  16. Lamela M, Anca J, Villar R, Otero J, Calleja JM. Hypoglycemic activity of several seaweed extracts. J Ethnopharmacol. 1989; 27(1-2):35-43.
  17. Schmidgall J, Schnetz E, Hensel A. Evidence for bioadhesive effects of polysaccharides and polysaccharide-containing herbs in an ex vivo bioadhesion assay on Buccal Membranes. Planta Med. 2000;66(1):48-53.
  18. Fujimura T, Tsukahara K, Moriwaki S, Kitahara T, Takema Y. Effects of natural product extracts on contraction and mechanical properties of fibroblast populated collagen gel. Biol Pharm Bull. 2000;23(3):291-7.
  19. Chevolot L, Mulloy B, Ratiskol J, Foucault A, Colliec-Jouault S. A disaccharide repeat unit is the major structure in fucoidans from two species of brown algae. Carbohydr Res. 2001;330(4):529-35.
  20. Haroun-Bouhedja F, Ellouali M, Sinquin C, Boisson-Vidal C. Relationship between sulfate groups and biological activities of fucans. Thromb Res. 2000;100(5):453-9.
  21. Bojakowski K, Abramczyk P, Bojakowska M, Zwolinska A, Przybylski J, Gaciong Z. Fucoidan improves the renal blood flow in the early stage of renal ischemia/reperfusion injury in the rat. J Physiol Pharmacol. 2001;52(1):137-43.
  22. Norman JA, Pickford CJ, Sanders TW, Waller M. Human intake of arsenic and iodine from seaweed-based food supplements and health foods available in the UK. Food Addit Contam. 1987;5(1):103-109.
  23. Phaneuf D, Cote I, Dumas P, Ferron LA, LeBlanc A. Evaluation of the contamination of marine algae (seaweed) from the St. Lawrence river and likely to be consumed by humans. Environ Res. 1999;80(2 Pt 2):S175-S182.
  24. Harrell BL, Rudolph AH. Kelp diet: A cause of acneiform eruption. Arch Dermatol. 1976;112:560.
  25. Lourdes R, Jorge R, Scott W, Dea H, Eliseo T. Risks and benefits of commonly used herbal medicines in Mexico. Toxicol Appl Pharmacol. 2008;1(227);125-135
  26. Fleming T, ed. PDR for Herbal Medicines. 2nd ed. Montvale, New Jersey: Medical Economics Company, 2000; p.107.
  27. Shilo S, Hirsch HJ. Iodine-induced hyperthyroidism in a patient with a normal thyroid gland. Postgrad Med J. Jul1986;62(729):661-2.
  28. Dimitriadou A, Frase R. Iodine goiter. Proc Royal Soc Med. 1961;54:345-346.
  29. Skibola CF. The effect of Fucus vesiculosus, an edible brown seaweed, upon menstrual cycle length and hormonal status in three pre-menopausal women: A case report. BMC Complement Altern Medl. 2004;4(10): PMC514561.